Disadvantages of LIPO ?

[Northy]

Certain things are down to the discression of the region, but Lipo is no one of them. Lipo will no be allowed at this years regionals.

G

[JCJC]

Originally Posted by mark christopher

sorry but that can not be true

brushless was allowed at regionals before nationals, and i see no tyre rules for regionals, so regionals can not run to the same rules as nationals.
im of the understanding its down to the discgretion on the region!
the 2008 battery rules will apply to nationals and not regional.brca sanctioned meeting in TC so presume off road will be the same

Must admit I do not fully understand it, but my answer was aimed at Lipo's and batteries not motors & tyres as that is what we are discussing. Here is a post from another thread on this subject, its a copy of a reply to a question I put to Jim Spencer:


Here is the (edited) reply I had from Jim Spencer

" Hi, Ok first off we're only taking about 1/10 Off Road Regionals, as they're the only class to run regional racing under the control of the full section commitee.

So the answer to your question is 'No' as the 1/10 Off Road rules don't allow LiPo's for any of their sanctioned events.

Any other sort of 'regional' event such as TORC or STCC from the touring car world then it's their choice.

Homologation works like this
When a section passes the rules for a new class it can - if it wishes - ask the Electric Board to draw up a homologation list (Bikes didn't bother) and the Touring Car section may well yet do so they're busy discussing that bit.
Assuming they do the E.B. would then contact the manufacturers asking for product to be supplied. (I suggested that a "vested interest" may propose & supply a sample-JCJC)

So in essence :-
No class uses them = no list.
1 class uses them = maybe a list > if they want one.
Get to a couple of classes and you'll definatly get a list.

The drivers in the classes need to vote in their use at Nationals to generate the info folks seem to want - almost as a comfort zone?

Hope this helps Jim -Jim Spencer "


Thread on RaceChat tucked away in the BRCA General Q&A forum,

http://www.rcracechat.com/vb/showthread.php?t=38852

http://www.rcracechat.com/vb/showthread.php?t=38896


I for one would like the chance to play with Lipo's at regional level, as the only Nationals we seem to do are the Juniors & F3's then National level is of little interest to me, I suspect NiMh punch to be of more importance to top drivers anyway.

[Cockerill]

Having used Lipo last weekend, it is stupidly fast and over powers the car far too much, however I changed nothing except putting a Lipo in. I for one wouldn't mind Lipo been run at regionals, but as far as I can gather from reading the rules they are not allowed at any BRCA sanctioned events (incl. regionals) for 2008.

With a class of touring cars running it this year and ROAR's approval it will give the BRCA a chance to see what/how it works over the next year and give them a lot more information regarding allowing it next year and what the best regulations are. Let them do the testing and then we can adopt whats best.

At the end of the day it all depends on a proposal been put forward and enough RACER'S voting it in at the AGM, just like with all rules.

As far as I can gather there was no proposal made for the 2007 AGM to allow Lipo at any BRCA events for 2008 so the one's who want it only have themselves to blame.

[mark christopher]

my mistake got the santioned bit the wrong way round.

Tom keep it till worksop finals weekend if you want to!!

[Cockerill]

Originally Posted by mark christopher

Tom keep it till worksop finals weekend if you want to!!

Cheers

It might be overpowered and far too fast but it's a lot of fun

[Mike Hudson]

Is there a prefered make of lipo to some people or are they all very much similar to each other performance wise?

[JCJC]

Looking at the Lipo "power outut" numbers.....20C 30C burst etc

For a layman in real terms whats the math ? please,

Say 5000mAh, would 20C be what, and how much would say a 10 double or 5.5 brushless draw? and the esc & servo or is that insignificant.

[mark christopher]

the c rating is the amps the pack can deliver trakpower 4900 is rated at 25C 122.5 Amp continuous, 30C 150 Amp max acceleration 50 nearly 250 Amp spikes
i doubt very much you will pull 122 amps continuous, the higher the c the more punch

[JCJC]

Cheers Mark, so our 5.5Brushless would be no problem on the trakpower, just need a protector.

[neiloliver]

What is needed is a true scientific head to head test during 2008. The new homologated NiMH cells Versus the latest Lithium Polymer offerings. Personally I dont think they (LiIon Polymer) should be allowed unless the products:

(1) Contain cells which carry UL1642 recognition
(2) Have on board protection circuit for over voltage (over charge) and under voltage (over discrage).
(3) Are hard cased in at least 1.50mm of UL94V-0 plastic.

This would make them 'proper' products, not cells linked together and which rely on the user to (i) balance them (ii) correctly set their charger so they dont dangerously over charge them (iii) Ruin them by over discharging them.

If you were asked to do these things with your laptop battery you would laugh!

Neil

[Chrislong]

Originally Posted by JCJC

burst etc

For a layman in real terms whats the math ? please,

MAH divided by 1000 = 1c. So a 5000mah is 5ah per 1C

Therefore 20c 5000mah packs = 5 x 20c = 100 amp continuous for 1hr = 100ah
5000mah 30c = 5 x 30c = 150 amp /1hr

Its funny how I can understand maths, but then minutes later I re-read what I write and it baffles me....

So, mark, so figures you state for 4900mah packs were actually 5000mah packs? or am I wrong with my maths? LOL. Im confused

Chris

[Chrislong]

Originally Posted by neiloliver

Personally I dont think they (LiIon Polymer) should be allowed unless the products:

(1) Contain cells which carry UL1642 recognition
(2) Have on board protection circuit for over voltage (over charge) and under voltage (over discrage).
(3) Are hard cased in at least 1.50mm of UL94V-0 plastic.

Neil

This would be good for all of us, makes them idiot-proof. But I take it the tourers have not adopted this? if not, does this mean if we take on Lipo in 2009 we have to go with a single homoligation list used by tourers too, i.e. is it too late for BRCA to enforce this for 2009 and so for the manufacturers to implement it in the pack. (... lots of what if's in there...)

[xx4-nutter]

Chris did the X-Factory Math

[Chrislong]

Originally Posted by xx4-nutter

Chris did the X-Factory Math

LOL, I so nearly said something too, but it was just too predictable!! ha ha

[xx4-nutter]

haha !

[mark christopher]

Originally Posted by neiloliver

What is needed is a true scientific head to head test during 2008. The new homologated NiMH cells Versus the latest Lithium Polymer offerings. Personally I dont think they (LiIon Polymer) should be allowed unless the products:

(1) Contain cells which carry UL1642 recognition
(2) Have on board protection circuit for over voltage (over charge) and under voltage (over discrage).
(3) Are hard cased in at least 1.50mm of UL94V-0 plastic.

This would make them 'proper' products, not cells linked together and which rely on the user to (i) balance them (ii) correctly set their charger so they dont dangerously over charge them (iii) Ruin them by over discharging them.

If you were asked to do these things with your laptop battery you would laugh!

Neil

neil i know you know your stuff, but if sence is used there fine, doing what you suggest would only do one more thing, make them more expensive.

Originally Posted by Chrislong

MAH divided by 1000 = 1c. So a 5000mah is 5ah per 1C

Therefore 20c 5000mah packs = 5 x 20c = 100 amp continuous for 1hr = 100ah
5000mah 30c = 5 x 30c = 150 amp /1hr

Its funny how I can understand maths, but then minutes later I re-read what I write and it baffles me....

So, mark, so figures you state for 4900mah packs were actually 5000mah packs? or am I wrong with my maths? LOL. Im confused

Chris

i used the text off trakpowers site!!

Originally Posted by Chrislong

This would be good for all of us, makes them idiot-proof. But I take it the tourers have not adopted this? if not, does this mean if we take on Lipo in 2009 we have to go with a single homoligation list used by tourers too, i.e. is it too late for BRCA to enforce this for 2009 and so for the manufacturers to implement it in the pack. (... lots of what if's in there...)

tourers are not having a pack list, nor are they having capacity cell counts etc
from what i have been told, there will be a max width and length, 7.4 volt max, and hard cased and thats about ur lot.
i know for fact that less lipo's have gone wrong this year, than nimh have had go wrong, and we have no saftey precautions for nimh